David Einhorn is pressing his short on Moody's in a multi-year duel with Warren Buffett.

NEW YORK ( TheStreet) - It might not be this quarter, but short-seller and professional poker player David Einhorn maintains ratings agency Moody's ( MCO) is poised for a big share fall as fraud allegations on its reviews of mortgage securities come to a head in 2013.

Einhorn -- who correctly predicted the demise of Lehman Brothers and recently set his gaze upon restaurant chain Chipotle Mexican Grill ( CMG) -- is sticking with the bet despite the fact that it's lost ground since being unveiled in the wake of the crisis and that he is facing off against bridge enthusiast Warren Buffett of Berkshire Hathaway ( BRK.A), who remains Moody's largest shareholder.

Buffett meanwhile has only pared his giant Moody's stake slightly since Einhorn conveyed his short bet and he's even defended the company in front congressional panels, to stinging criticism.

Now, with only one count remaining against Moody's and its competitor -- McGraw-Hill ( MHP) owned Standard & Poor's -- on a key lawsuit tied to pre-bust mortgage bond ratings, the score between Einhorn and Buffett is likely soon to be settled once and for all.

At the Value Investing Congress on Tuesday, Einhorn said so much, in a presentation that also outlined the investing logic behind other headline-grabbing investments such as short positions on Green Mountain Coffee Roasters ( GMCR) and Chipotle, and a conviction that election year politics are clouding an otherwise bright outlook for General Motors ( GM) and Cigna ( CI).

The contest between Einhorn and Buffett pits conflicting opinions on the extent to which Moody's and S&P can be held financially responsible for mortgage bond ratings that proved to be wildly inaccurate after the housing bust.

In September, a judicial ruling on lawsuits against Moody's and S&P's signal investors can continue to pursue fraud charges against the agencies, in litigation that casts doubt on whether ratings opinions can be protected by First Amendment free speech rights if a fraud can be proven.

After the ruling expunged all but a fraud charge against Moody's and S&P on a mortgage security it rated for Morgan Stanley ( MS), Einhorn said at the Congress on Tuesday that when the case comes to a head in early 2013, it could open a Pandora's Box of legal issues that would destroy their business model and finances of rating agencies.

"Its a matter of time before they all disappear," said Einhorn, of the rating agencies, in response to an audience question asking for an update on his short thesis.